Lubricant



Patente July 12, 1946;

attach naroAN'r John A. Patterson, Beacon, N.

Texas Company, New York, N.

tion of Delaware Y., assignor to The Y., a corpora- This invention relates to the use of sulfurized derivatives of compositions derived from cashew nut shell oil in hydrocarbon oils, particularly petroleum oils, to improve the properties ofthe lu bricants compounded therewith.

The naturally occurring cashew nut shell oil is described in Matiello, J. J Protective ti Decorative Coatings, chap. 2, (19%.) as containing approximately 90% anacardlc acid (C22H32O3) and cardol (Carlie-.104) when extracted from the shells by means of solvents. This composition is very unstable and is subject to polymerization, condensation and decomposition on heating.

The usual commercial methods of extracting the oil from the cashew nut shells areincidental to the extraction of the kernel. The cellular ture of the shell is destroyed by a thermal treatment such as a charring or carbonizing process which expells'the oil and facilitates removal of the kernel. The extracted shell oil is collected as a dark, thick, viscous liquid whose chemical composition varies in accordance with the degree of heat used in the extraction process.

These thermally extracted oils are described as consisting primarily of anacardic acid, cardanol. (CzoHazO) and cardol with cardanol predornlnating. The particular proportions of these components vary inv accordance with the amount of heat used in the extraction process as, for ex-- ample, when extracting at low temperatures of approximately 400 F., the extracted oil contains approximately 70% cardanol, whereas extracting at roasting temperatures yields an oil containing aproximately 40-50% cardanol. 2

It has been discovered that the addition of a small quantity of an oil-soluble or oil-miscible sulfurized derivative of cardanol to a refined hydrocarbon oil provides a lubricant or a compounding lubricant which possesses enhanced antioxidant or anti-corrosive properties.

The refined hydrocarbon oils which may be improved by the compositions of the present inven- 'tion include the petroleum lubricating oils used as motor, Diesel, turbine and aviation oil and such hydrocarbon oils as are used in industrial lubricants, greases, textile oils, etc.

Distillation of the commercial cashew nut shell oil carried out either at greatly reduced pressure or steam distillation at atmospheric or reduced pressure yields a distillate consisting almost entirely of cardanol. light colored liquid at approximately 225 C. and 10 mm. mercury. This compound is described as a phenol derivative possessing an unsaturated alkyl radical in the meta position. This coms Glaims. (Cl. 252-482) strucpound is very unstable and upon heating forms condensation and polymerization products, together with co-polymers. In addition to the cardanol, the distillate obtained contains a lower boiling fraction possessing a. .nicotinerlike odor when exposed to the atmosphere. This fraction which amounts to about 5%of the original oil contains approximately 0.64% nitrogen. fraction may be separated' by fractional distillation.

Another method of obtaining cardanol is the destructive distillation of the solvent extracted cashew nut shell oil. The yields obtained will vary according to the degree of decomposition of the solvent extracted oil. The following physical' constants were "obtained on a sample of a distillate obtained by distilling the commercially available thermal extracted cashew nut shell oil at 10 mmJHg.

which rapidly darkens Bromine No 135 Hydroxyl N0 183 Neutralization No d Refractive index Ncu uu 1.4973

I The term cardano as used throughout the specification and claims, unless otherwise stated, is meant to include not only the specific compound which has a constant boiling point at a'ppro" mately 225 C. and 10 mm. Hg but also the distillation products obtained by the distillation of the thermal extracted cashew nut shell oil at re- Cardanol distills over as a duced pressures or by steam distillation at atmospheric or reduced pressure and the distillate oletained by the destructive distillation of the solvent extracted cashew nut shell oil together with such fractions obtained from cashew nut shell oil which contain a major portion of cardanol.

These oil-soluble or oil-miscible sulfurized derivatives of the present invention may be incorporated in a hydrocarbon oil in amounts varying between 0.01 to 5% by weight of the finished lubricant. The particular pend upon the type of lubricant to be improved, the service for which the lubricant is intended and the degree of improvement desired in the by drocarbon oil. It is to be noted that in many instances, especially in the compounding of lubricating oils, the additives of the present invention will be used in combination with a detergent additive in the finished lubricant and, therefore. the amounts used will depend upon the type of detergent additive together with its compatibility. The preferred range of proportions in a mineral If desired, this lower boiling proportions used delubricating oil when used in a few of the more common services are as follows:

Per cent by weight of finished lubricant Diesel lubricating oil 0.5 2.5 Motor lubricating oil 0.5 -'3.0 Heavy duty lubricating oil 0.5 -3.0 Turbine lubricating oil 0.01-0.10 Airplane lubricating oil 0.5 -2.0

In preparing the oil-soluble sulfurized derivatives care must be taken-to avoid the polymerization reactions which normally attend the addition of sulfur to cardanol. In the usual reaction of sulfur with cardanol, polymerization products are obtained which range from semi-solid to solid rubbery materials whichare oil-insoluble. It has been found preferable to avoid these reactions by stabilizing the cardanol' prior to the sulfurizeti'on'reacticns by means of a hydrogenation reaction which reduces the degree of unsaturation. In this manner the cardanol is rendered suflle ciently stable as to enable a majority of the usual sulfurization reactions to be employed in preparing the oil soluble derivative, v

Although it is preferred to use a stabilizing reaction such as partial hydrogenation prior to sulfurizati'on, other methods may be employed.

One of these methods which avoids the hydrogenation step and still produces an oil-soluble product is the direct sulfurization with sulfur, at

low temperatures, in the presence of solvent diluents such as lubricating oil, xylenes, etc. In every instance the amount of sulfur which may be incorporated intothe unsaturated constituents of 'cardanol will depend upon the degree of unsaturation. The following examples illustrate two- R of the methods which might be used in preparing the foregoing types of additives:

EXAMPLE I"- An ethyl alcohol solution of 514 grams of the i i Q distillate obtained from the, distillation of commerclally available cashew nut shell oil was j charged in a hydrogenation bomb with -15 grams of Raney nickel catalyst and treated'with hydrogen under pressure. 1 controlled by external heat and varied between 50 F. at the start to 200 F. near the i product, after being freed of catalyst and solv vent, weighed 495 grams and had a bromine number of 80. 1000 grams of the partially hydro-.

end. The

genated cardanol and 115 grams of sulfur were 7 heated together at 150-155 C. for 3 hours. i The sulfurized product was dissolved in an equal weight of lubricating oil to form a 50% concen- EXAMPLE II t 100 grams of cardanoi (distillate obtained from I trate.

:vacuum distillation of thermal extracted cashew nut shell oil) with a bromine number of 135 was .dissolved in 100 grams of lubricating oil and 260 cc. of xylene.- 23 grams of sulfur was added to the solution and the mixture heated at 145-148 C. for 5 hours. The resulting clear, dark-colored solution was cooled to room temperature and allowed to set overnight. The resulting sulfurized product formed a clear solution in the lubricating oil.

\ The effectiveness of the cpmposition of the present invention as improvinEagents for lubricants was demonstrated by an empirical test designed to demonstrate the anti-oxidant or anticorrosive properties of the additive ingredient of a lubricating oil. This test consists of a cop- 4 per-lead bearing specimen encased in a special non-wearing bushing. rotativ'ely mounted on a stainless steel shaft and immersed in'a glass pot of the oil.to be tested. The oil was heated to a controlled temperature of either 250 F. or 350 I".

and continuously circulated between the bearing specimen and the shaft for 10 hours. Throughout the test the oilwas continuously agitated by means of copper baflies which acted as oxidation accelerators. The bearing specimen was weighed before the test and after the 10-hour period and the loss of weight recorded in milligrams. The reference oil of this test was a solvent-refined, dewaxed, Mid-Continent lubricating oil of an SAE 30 grade. The following results were obtained on the uninhibited jreference oil and the reference oil com-pounded with anadditive of the present invention:

BEARING Coxaosrom-Corrzn Luv (10 Hones) Loss of weight, mas.

Reference oil 13 153 Reference oil+1.0% oi sulfurized partially hydrogenated cardanol (Example I) 0 92 i The hydrocarbon oils to which the oil-soluble sulfurizedderivatives of the present invention are added may be either in the crude form or partially or highly refined and may contain other additive ingredients such as dyes, metal soaps,

-pour depressants.- thickeners, V. I. improvers, oilisludge disand corrosion inhibiness agents, extreme pressure agents, persers,'oxidation inhibitors,

' tors such as sulfurized hydrocarbons, etc.

' The sulfurized derivatives of the subject inguished from the reaction The temperature was should be imposed as.

pended claims.

v of reaction, yields elemental vention are those produced by the reaction with sulfur which is obtained from sulfur per se, or from a sulfurizing agent w ich, under conditions sulfur. The sulfurized derivatives so produced are to ,be distin products obtained by reaction with a phosphorus sulfide which is not 1i;i1'icluded'within the scope of the present inven- Obviously many modifications and variations of the invention, as hereinbefore set forth. may be made without departing from the spirit and scope thereof and, therefore, only such limitations are indicated in the a tially hydrogenated phenolic distillate obtained from the'distillation of cashew nut shelloil.

5. A lubricant comprising a hydrocarbon oil and a small quantity of an oil-soluble sulfurized derivative of cardanol. said quantity being sufll v cient to impart anti-oxidant properties to said hydrocarbon oil constituent.

JOHN A. PATTERSON.

comprising a hydrocarbon oil comprising a hydrocarbon oil Disclaimer 2,403,234.J0hn A. Patterson, Beacon, N. Y. LUBRICANT. Patent dated July 2, 1946. Disclaimer filed Apr. 11, 1949, by the assignee, The Texas Company.

Hereby enters this disclaimer to claim 4 of said patent.

[Oficial Gazette May 10, 1.949.] 

